linux-ext4 - [PATCH V7 01/12] ext4: add a function which extends a group without checking parameters

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Message-Id: <1325653654-10478-2-git-send-email-tytso@mit.edu>
Date:	Wed,  4 Jan 2012 00:07:23 -0500
From:	Theodore Ts'o <tytso@....edu>
To:	Ext4 Developers List <linux-ext4@...r.kernel.org>
Cc:	Yongqiang Yang <xiaoqiangnk@...il.com>,
	"Theodore Ts'o" <tytso@....edu>
Subject: [PATCH V7 01/12] ext4: add a function which extends a group without checking parameters

From: Yongqiang Yang <xiaoqiangnk@...il.com>

This patch added a function named ext4_group_extend_no_check() whose code
is copied from ext4_group_extend().  ext4_group_extend_no_check() assumes
the parameter is valid and has been checked by caller.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@...il.com>
Signed-off-by: "Theodore Ts'o" <tytso@....edu>
---
 fs/ext4/resize.c |   51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 51 insertions(+), 0 deletions(-)

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 996780a..1c3c2b5 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -969,6 +969,57 @@ exit_put:
 } /* ext4_group_add */
 
 /*
+ * extend a group without checking assuming that checking has been done.
+ */
+static int ext4_group_extend_no_check(struct super_block *sb,
+				      ext4_fsblk_t o_blocks_count, ext4_grpblk_t add)
+{
+	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+	handle_t *handle;
+	int err = 0, err2;
+
+	/* We will update the superblock, one block bitmap, and
+	 * one group descriptor via ext4_group_add_blocks().
+	 */
+	handle = ext4_journal_start_sb(sb, 3);
+	if (IS_ERR(handle)) {
+		err = PTR_ERR(handle);
+		ext4_warning(sb, "error %d on journal start", err);
+		return err;
+	}
+
+	err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
+	if (err) {
+		ext4_warning(sb, "error %d on journal write access", err);
+		goto errout;
+	}
+
+	ext4_blocks_count_set(es, o_blocks_count + add);
+	ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
+		   o_blocks_count + add);
+	/* We add the blocks to the bitmap and set the group need init bit */
+	err = ext4_group_add_blocks(handle, sb, o_blocks_count, add);
+	if (err)
+		goto errout;
+	ext4_handle_dirty_super(handle, sb);
+	ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
+		   o_blocks_count + add);
+errout:
+	err2 = ext4_journal_stop(handle);
+	if (err2 && !err)
+		err = err2;
+
+	if (!err) {
+		if (test_opt(sb, DEBUG))
+			printk(KERN_DEBUG "EXT4-fs: extended group to %llu "
+			       "blocks\n", ext4_blocks_count(es));
+		update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, (char *)es,
+			       sizeof(struct ext4_super_block));
+	}
+	return err;
+}
+
+/*
  * Extend the filesystem to the new number of blocks specified.  This entry
  * point is only used to extend the current filesystem to the end of the last
  * existing group.  It can be accessed via ioctl, or by "remount,resize=<size>"
-- 
1.7.8.11.gefc1f.dirty

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